Buggy code:
, new Fraction [ ] { new Fraction ( 7 , 2 ) , new Fraction ( 9 , 2 ) } } ; protected Fraction [ ] [ ] subRows23Cols00 = new Fraction [ ] [ ] { new Fraction [ ] { new Fraction ( 2 ) } , new Fraction [ ] { new Fraction ( 4 ) } } ; protected Fraction [ ] [ ] subRows00Cols33 = new Fraction [ ] [ ] { new Fraction [ ] { new Fraction ( 4 ) } } ; protected Fraction [ ] [ ] subRow0 = new Fraction [ ] [ ] { new Fraction [ ] { new Fraction ( 1 ) , new Fraction ( 2 ) , new Fraction ( 3 ) , new Fraction ( 4 ) } } ; protected Fraction [ ] [ ] subRow3 = new Fraction [ ] [ ] { new Fraction [ ] { new Fraction ( 4 ) , new Fraction ( 5 ) , new Fraction ( 6 ) , new Fraction ( 7 ) } } ; protected Fraction [ ] [ ] subColumn1 = new Fraction [ ] [ ] { new Fraction [ ] { new Fraction ( 2 ) } , new Fraction [ ] { new Fraction ( 5 , 2 ) } , new Fraction [ ] { new Fraction ( 4 ) } , new Fraction [ ] { new Fraction ( 5 ) } } ; protected Fraction [ ] [ ] subColumn3 = new Fraction [ ] [ ] { new Fraction [ ] { new Fraction ( 4 ) } , new Fraction [ ] { new Fraction ( 9 , 2 ) } , new Fraction [ ] { new Fraction ( 8 ) } , new Fraction [ ] { new Fraction ( 7 ) } } ; protected double entryTolerance = 1.0E-15 ; protected double normTolerance = 1.0E-13 ; @ Test public void testDimensions ( ) { } @ Test public void testCopyFunctions ( ) { } @ Test public void testAdd ( ) { } @ Test public void testAddFail ( ) { } @ Test public void testPlusMinus ( ) { } @ Test public void testMultiply ( ) { } private Fraction [ ] [ ] d3 = new Fraction [ ] [ ] { new Fraction [ ] { new Fraction ( 1 ) , new Fraction ( 2 ) , new Fraction ( 3 ) , new Fraction ( 4 ) } , new Fraction [ ] { new Fraction ( 5 ) , new Fraction ( 6 ) , new Fraction ( 7 ) , new Fraction ( 8 ) } } ; private Fraction [ ] [ ] d4 = new Fraction [ ] [ ] { new Fraction [ ] { new Fraction ( 1 ) } , new Fraction [ ] { new Fraction ( 2 ) } , new Fraction [ ] { new Fraction ( 3 ) } , new Fraction [ ] { new Fraction ( 4 ) } } ; private Fraction [ ] [ ] d5 = new Fraction [ ] [ ] { new Fraction [ ] { new Fraction ( 30 ) } , new Fraction [ ] { new Fraction ( 70 ) } } ; @ Test public void testMultiply2 ( ) { } @ Test public void testPower ( ) { } @ Test public void testTrace ( ) { } @ Test public void testScalarAdd ( ) { } @ Test public void testOperate ( ) { FieldMatrix < Fraction > m = new Array2DRowFieldMatrix < Fraction > ( id ) ; TestUtils . assertEquals ( testVector , m . operate ( testVector ) ) ; <START_BUG> TestUtils . assertEquals ( testVector , m . operate ( new ArrayFieldVector < Fraction > ( testVector ) ) . getData ( ) ) ; <END_BUG> m = new Array2DRowFieldMatrix < Fraction > ( bigSingular ) ; try { m . operate ( testVector ) ; Assert . fail ( "Expecting<seq2seq4repair_space>illegalArgumentException" ) ; } catch ( MathIllegalArgumentException ex ) { } } @ Test public void testMath209 ( ) { } @ Test public void testTranspose ( ) { } @ Test public void testPremultiplyVector ( ) { } @ Test public void testPremultiply ( ) { } @ Test public void testGetVectors ( ) { } @ Test public void testGetEntry ( ) { } @ Test public void testExamples ( ) { } @ Test public void testGetSubMatrix ( ) { } private void checkGetSubMatrix ( FieldMatrix < Fraction > m , Fraction [ ] [ ] reference , int startRow , int endRow , int startColumn , int endColumn ) { } private void checkGetSubMatrix ( FieldMatrix < Fraction > m , Fraction [ ] [ ] reference , int [ ] selectedRows , int [ ] selectedColumns ) { } @ Test public void testCopySubMatrix ( ) { } private void checkCopy ( FieldMatrix < Fraction > m , Fraction [ ] [ ] reference , int startRow , int endRow , int startColumn , int endColumn ) { } private void checkCopy ( FieldMatrix < Fraction > m , Fraction [ ] [ ] reference , int [ ] selectedRows , int [ ] selectedColumns ) { } @ Test public void testGetRowMatrix ( ) { } @ Test public void testSetRowMatrix ( ) { } @ Test public void testGetColumnMatrix ( ) { } @ Test public void testSetColumnMatrix ( ) { } @ Test public void testGetRowVector ( ) { } @ Test public void testSetRowVector ( ) { } @ Test public void testGetColumnVector ( ) { } @ Test public void testSetColumnVector ( ) { } private FieldVector < Fraction > columnToVector ( Fraction [ ] [ ] column ) { }

Fix:
TestUtils . assertEquals ( testVector , m . operate ( new ArrayFieldVector < Fraction > ( testVector ) ) . toArray ( ) ) ;